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| author | Dmitry Safonov <dsafonov@virtuozzo.com> | 2017-03-06 17:17:18 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2017-03-13 14:59:22 +0100 |
| commit | 8f3e474f3cea7b2470218a6ed6da47ff02147dce (patch) | |
| tree | ffb74bdfb6bf952a893afb5425903a906eeec8ff /arch/x86/include/asm | |
| parent | 6a0b41d1e23dd3318568461593ae5e36d966981e (diff) | |
| download | lwn-8f3e474f3cea7b2470218a6ed6da47ff02147dce.tar.gz lwn-8f3e474f3cea7b2470218a6ed6da47ff02147dce.zip | |
x86/mm: Add task_size parameter to mmap_base()
To correctly handle 32-bit and 64-bit mmap() syscalls in 64bit applications
its required to have separate address bases to place a mapping.
The tasksize can be used as an indicator to select the proper parameters
for mmap_base().
This requires the following changes:
- Add task_size argument to mmap_base() and make the calculation based on it.
- Provide mmap_legacy_base() as a seperate function
- Use the new functions in arch_pick_mmap_layout()
[ tglx: Massaged changelog ]
Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: 0x7f454c46@gmail.com
Cc: linux-mm@kvack.org
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Link: http://lkml.kernel.org/r/20170306141721.9188-3-dsafonov@virtuozzo.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/include/asm')
| -rw-r--r-- | arch/x86/include/asm/elf.h | 24 | ||||
| -rw-r--r-- | arch/x86/include/asm/processor.h | 4 |
2 files changed, 16 insertions, 12 deletions
diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h index 9d49c18b5ea9..b908141cf0c4 100644 --- a/arch/x86/include/asm/elf.h +++ b/arch/x86/include/asm/elf.h @@ -293,8 +293,19 @@ do { \ } \ } while (0) +/* + * True on X86_32 or when emulating IA32 on X86_64 + */ +static inline int mmap_is_ia32(void) +{ + return IS_ENABLED(CONFIG_X86_32) || + (IS_ENABLED(CONFIG_COMPAT) && + test_thread_flag(TIF_ADDR32)); +} + #ifdef CONFIG_X86_32 +#define __STACK_RND_MASK(is32bit) (0x7ff) #define STACK_RND_MASK (0x7ff) #define ARCH_DLINFO ARCH_DLINFO_IA32 @@ -304,7 +315,8 @@ do { \ #else /* CONFIG_X86_32 */ /* 1GB for 64bit, 8MB for 32bit */ -#define STACK_RND_MASK (test_thread_flag(TIF_ADDR32) ? 0x7ff : 0x3fffff) +#define __STACK_RND_MASK(is32bit) ((is32bit) ? 0x7ff : 0x3fffff) +#define STACK_RND_MASK __STACK_RND_MASK(mmap_is_ia32()) #define ARCH_DLINFO \ do { \ @@ -348,16 +360,6 @@ extern int compat_arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp); #define compat_arch_setup_additional_pages compat_arch_setup_additional_pages -/* - * True on X86_32 or when emulating IA32 on X86_64 - */ -static inline int mmap_is_ia32(void) -{ - return IS_ENABLED(CONFIG_X86_32) || - (IS_ENABLED(CONFIG_COMPAT) && - test_thread_flag(TIF_ADDR32)); -} - /* Do not change the values. See get_align_mask() */ enum align_flags { ALIGN_VA_32 = BIT(0), diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index f385eca5407a..7caa2ac50ea2 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -797,6 +797,7 @@ static inline void spin_lock_prefetch(const void *x) /* * User space process size: 3GB (default). */ +#define IA32_PAGE_OFFSET PAGE_OFFSET #define TASK_SIZE PAGE_OFFSET #define TASK_SIZE_MAX TASK_SIZE #define STACK_TOP TASK_SIZE @@ -873,7 +874,8 @@ extern void start_thread(struct pt_regs *regs, unsigned long new_ip, * This decides where the kernel will search for a free chunk of vm * space during mmap's. */ -#define TASK_UNMAPPED_BASE (PAGE_ALIGN(TASK_SIZE / 3)) +#define __TASK_UNMAPPED_BASE(task_size) (PAGE_ALIGN(task_size / 3)) +#define TASK_UNMAPPED_BASE __TASK_UNMAPPED_BASE(TASK_SIZE) #define KSTK_EIP(task) (task_pt_regs(task)->ip) |